Given the world's preoccupation by economic constraints, one could argue that this is not the best time for an intergovernmental sustainability summit. Timing aside, a predictable policy direction, including priced externalities, corporate reporting requirements and reform of the UN sustainability structure is needed to incentivise bold action towards green growth.

Recent elections or leadership changes in many countries have focused attention on affairs at home, providing important local action but risking short-termism and ultimately short-term prosperity.

Thus, the preparations for the UN Rio+20 summit have not been what they could have been – and seem to pale in comparison with the runup to the original Rio Earth summit in 1992 where three international treaties were ready to be signed. While the world has moved forward in 20 years, it is highly unlikely any formal treaty will be signed.

Short-term thinking comes with severe risks. Global megaforces, such as population growth, natural resource scarcity, biodiversity loss and climate change are impacting our planet, our economy and ourselves. It is now of utmost importance not to remain preoccupied by the more temporary issues, but to grasp opportunities arising from these megaforces, remaining competitive in the long run.

Rio provides an opportunity for momentum towards a more sustainable economy. Business has shown the ability to lead the way towards green growth by enhancing cost effectiveness, reducing impacts on the supply chain and by collaborating to retain natural resources.

But business cannot pave the way towards a green economy in isolation. The policy framework in which business has to operate is of crucial importance for sound progress. I envision four main aspects of such a regulatory framework that would spur action towards a green economy.

Long-term sustainability and climate change policy goals are needed

The main culprit preventing investors from transitioning towards greener investment portfolios is the lack of predictability in policy direction, which is often subject to change in favour of short-term economic benefit or political populism. So clarity, predictability, transparency and stability of policy is an essential requirement for green growth.

Governments must lead the way

Secondly, an encompassing playing field is needed, in which externalities of economic activity are internalised. A government framework is needed to facilitate this, where the external effects of social and environmental costs are properly priced and scarcity is integrated into the price of all common goods such as air, water and minerals. Needless to say, a fair price for goods and services incentivises producers and consumers to transition towards more sustainable business. Tax system reform is another way to achieve this. The International Energy Agency, for example, has calculated that subsidies for renewable energy amounted to $64bn (£41bn) in 2010, whereas subsidies for fossil amounted to $409bn. It's obvious that governments are pivotally positioned to reform this system and need to lead the way.

Comply or explain

Thirdly, governments should encourage business to enhance transparency on their business functions, ideally via a framework where business couples financial and non-financial information as well as reporting. Minimum sustainability reporting requirements for stock-listed companies, including a "comply or explain" rule on material sustainability issues could stimulate substantive corporate board discussions on risks and opportunities arising from sustainability issues. This could then result in true integration of sustainability within business operations, making business stronger agents of change towards a green economy.

These three actions towards a stable regulatory framework can be categorised under the Rio agenda known as "the green economy in the context of sustainable development and poverty eradication", an item that has resonated well in many spheres lately. Although less attention has been paid to the other Rio agenda item, "the institutional framework for sustainable development", it should not be underestimated as an element for success in the regulatory framework.

The fourth aspect, a new UN Sustainability Framework, can also help to provide the necessary support for a progressive, global sustainability agenda.

Despite the UN secretary general's work to engage member states into sustainability and climate meetings and the efforts to bringing the climate negotiations under the sustainability umbrella, the UN system seems to be insufficiently coordinated to be able to really make sustainability a priority. Hence, it is important that the secretary general is explicitly mandated to mobilise the UN system to support national strategy development and implementation and that through him, or her, different UN organisations are held accountable for how they deliver on national needs and priorities.

Decisions made by all parts of the UN, including the World Bank, must be in line with this. As a consequence, the activities undertaken by different UN agencies to develop and implement a particular national strategy, would need to be explicitly identified under the overall responsibility of a single UN agency or institution.

This can only be made to work if the governing bodies of individual organisations explicitly support such an approach. In the end, the greatest battle regarding coherence of the UN system needs to be fought in national capitals, not New York.

The green growth business case can be made convincingly if governments implement a stable regulatory framework, including proper pricing of externalities, and by means of the right incentives for corporate transparency, facilitating a green transition. Importantly, the UN system can contribute more strongly to this transition through institutional reform with a more co-ordinated approach.

Only broad conviction of the policy direction will unlock global capital flows towards green economic growth. Leadership from heads of state and business is needed now, perhaps more than ever, to achieve that. Leadership to help future proof our global economy, towards the future we want.

Yvo de Boer is special global advisor at KPMG Global Climate Change and Sustainability Services